the engine shaft, and the "forking" or pumping out of a fooded mine, are operations requiring much practical experience and considerable skill. Previous to the introduction of the steam engine the influx of water and the difficulties of drainage limited, in a very short time, the depth to which it was practicable to sink shafts. In old times the water had to be raised by buckets, hand-pumps, and similar devices. In parts of Japan hand-pumps are still used having wooden barrels, the water being raised by a series of short lifts. In some of the deeper mines of Cornwall, previous to the introduction of the steam engine, horses were attached to a whim which worked the pumps; this proved a most harassing expedient. Early in the last century Savery proposed a method of raising water into a varaum produced by the condensation of steam. This method does not appear to have attained much practical success. Shortly afterwards Newcomen devised his engine, which soon developed into the Savery-Newcomen type of atmospheric engine, and was perfected in the hands of Smeaton. It was largely employed for pumping water from mines. In 1765 Watt's discovery of a separate condenser, and the various adjuncts he introduced, caused the atmospheric engine to be completely superseded by the Watt steam engine, from which was very soon evolved the Cornish pamping engine, one of the most economic engines known for the pumping of water. This engine has rendered depths accessible that were previously considered impracticable: Ilcoath, the deepest mine in Cornwall, being down 420 fathoms, or very nearly half a mile. The Cornish pumping ege is a single-acting engine; steam being admitted above the piston depresses it and brings down the inner end of the beam-this is called the "indoor stroke;" on opening communication between the upper and lower sides of the peston equilibrium is established, and the weight of the pump rods, &c., lowers the outer end of the beam, thus making the "outdoor stroke." In the early days of the pping engine all the lifts were drawing lifts-like those of an crinary suction pump; but on the invention of the pger lift it was adopted for mining, and is now applied most all mines (except for the lower two lifts, where Le drawing lift is preferable), forcing the water to the sariace by a succession of lifts, generally from 40 to 50 tims high. The pump rods are made of sufficient weight to more than counterbalance the column of water; the exass of weight is taken off by balance bobs, water columns, erther counterpoise. During the indoor stroke the engine La to raise the weight of the rods plus the weight of water the drawing lifts, and has to fill the plunger barrels ; caring the outdoor stroke the weight of the rods forces the mtents of each plunger barrel up the height of its lift. Of ether engines used for pumping, the Bull engine has the der placed directly over the shaft, and the pump rods "aced direct to the piston, so that the rods are raised by the steam without the intervention of a beam. This plan ates the necessity of a substantial engine-house; but tre are serious objections to the blocking up of the mouth the shaft. Horizontal engines are applied to pumping; they need, however, the intervention of angle bobs, with &c., which increase complications. In many collieries re there is a wide lateral space in which the water may Araiate, in case of mishap to the engine a direct-acting he is placed underground, that forces the column of Vater direct up to the surface without needing the addition of pump rods. In metalliferous mines, where at the bottom there is small accumulating space, and where the water rises rap dly that in case of an accident the engine might be bmerged before it could be repaired, such a plan, though having many advantages, is hardly applicable. The pumps in a mine are now almost always made of iron, and they vary in diameter up to about 20 inches, but for very deep mines they are seldom put in larger than about 10 or 14 inches diameter. The bottom lift is always MINES. a drawing lift, so that it can be operated from above in case of the water rising. At the bottom there is a perforated nozzle for taking in the water-the snore piece; when the engine is keeping the water at its proper level this takes in air towards the end of each stroke, hence the name, and the engine is said to be working in fork. Some feet above the snore piece there is a valve, the lower clack, that is accessible through a hole in the side closed by an iron door; this is the door piece. Above this comes the working barrel, in which the pump bucket works. The bucket consists of an iron framework edged round with a ring of strong leather; the valve also is of leather. When Fig. 3. Fontaine's Safety-cage (parachute). Scale, one-fiftieth. the leather wears out the bucket has to be changed, gearing the buckets, or fitting them with leather, being the pitman's special duty. The bucket is attached generally to an iron rod, that is joined on to the main pump rod; it draws out usually at the top of the lift. The plunger works like an ordinary force-pump; there is a snore piece, but it should always be submerged, as air in the barrel impairs the working of the plunger. The H-piece is a large casting so called from its form, which makes communication be tween the plunger barrel and the column of pumps. At the base of the column there are two valves, one above the other-the lower and upper clacks-and separated by the passage to the plunger pole; during the upward or indoor stroke the lower clack opens, admitting water below the plunger; during the outdoor stroke this closes, and the upper clack is opened by the water being forced up the column to the next lift. The pump rods are made of square timber, varying in size according to the depth of shaft and size of pumps; they are provided with guides, and catch pieces or projections that rest on special Fig. 4. supports in case of breakage or stoppage; in inclined shafts they rest on rollers, and at an angle or change of inclination in the shaft angle bobs or fend-off pieces are put in. In deep shafts, in order to take off the excess of weight, balance bobs are also adopted. The Man-engine, with double mov able ladder. The means of winding stuff in a shaft have been greatly improved of late. In small shafts, the kibble or iron bucket attached to a horse whim is still retained, but for deep shafts the skip and cage are now much more general. The skip is a long iron box of rectangular cross section; to it are attached wheels, that run on a specially prepared road the skip road -down the shaft. The ore is filled in from the plat or receptacle at the side of the shaft, and the skip drawn to the surface; on knocking out a pin an opening is made through which the stuff falls into a waggon placed to receive it. Some skips are made automatic or self-tipping. With a cage the ore receives less tranship ment: in this there are platforms on which the MINES. The winding may be performed by a horizontal engine or by a Cornish double-action rotary engine. Formerly the horse whim or gin was much used, but except for small or temporary shafts this is not now much employed. It consists of a horizontal drum round which the chains or ropes are wound; two projecting arms serve for yoking the horses that work the machine. In some cases the hand windlass or tackle is still employed. The facilities for the ascent and descent of the miners are of the utmost importance. A good ladder, road, or footway should always be provided; but in deep mines after a heavy core's work this is a most laborious method of egress. In mines where cages are employed the miners are generally raised by winding. In many mines the man-engine or Fahrkunst is used. Fig. 4 represents a double man-engine. This consists of two parallel reciprocating rods, to which small platforms are attached, and which are actuated by a proper engine. Suppose a man to be ascending he stands on one platform while that rod is moving upwards; when it comes to the end of its stroke he steps to the platform on the other rod, and so on. When going down the reverse is the case, the man always getting on to the platform of the descending rod. With a single-rod man-engine the man rests on a fixed platform while the rod is making the stroke the reverse of the direction in which he wishes to proceed. The double-rod man-engine was used in the Hartz mines in 1834. In this country the first was erected at Tresavean, Cornwall, in 1843. A single-rod engine was erected at Fowey in the same county in 1851. This form is now used in most of the deep mines of the country. The importance of proper ventilation in mines has been fully recognized in recent years. In metalliferous mines the engine shaft, being the deepest, is usually the upeast shaft; the air proceeds down the other shafts, and after being conveyed through the stopes and pitches, enters this shaft through the lowest level. Various supplementary means have often to be adopted for ventilating remete ends and headings. The use of compressed air for driving the boring machines has greatly improved the condition of many of these places; by turning the end of the air-pipe into a pipe of larger diameter a very effective ventilator may be constructed on the same principle as the steam blast. The water trompe or blast propelled by a colum of falling water is a favourite method of forcing air to a working place, and the air so obtained is often much preferred by the miner; it is cool and no doubt has much of the smoke and noxious vapours washed out of it. The fan machine is another favourite device, also the method of pipes leading from a door or other stoppage in the natural earrent of circulation. In coal-mines the matter of ventila tion has to be far better attended to, on account of the risk of explosion, and artificial means are often resorted to is order to promote it; these may consist of a furnace in the upeast shaft, or the application of an exhaust fan, such as that of Guibal: the air as it descends is split up into number of separate currents that are conveyed to the different workings, and eventually to the outlet or upeast shaft. The lighting of mines in this country is usually effected by candles, a piece of moist clay serving to prevent it from wasting and as a candlestick for attaching it to the s or in other places. The manipulation of his clay is a crucial test of a true miner. In some districts small falling down the shaft in case of a breakage. When the owing to the explosive nature of the gases that often emslamps burning oil or solid paraffin are used. In coal-mines, the catches outward so as to become embedded in the used; this is the safety-lamp, first invented by Davy, who rope breaks the spring comes into action, and thrusts nate from the beds, a special form of lamp has often to be runners or guide rods, and so keep the whole suspended discovered that by inclosing the light in fine wire ganze t employed for winding purposes; they have many advan- flame could not pass through the gauze under ordinary Wire ropes are now generally temperature became reduced to such an extent that the conditions and ignite the surrounding atmosphere. In its in the shaft, as shown. tages over the old iron chains. the original form the gauze cut off a large amount of light, but several improvements have been effected upon it since. Some of these are represented in figs. 5, 6, 7. Previous to the introduction of these lamps an iron wheel working against flints was the light used in fiery places, and in some mines it was the practice to ignite the fire-damp at stated hours when the men were absent. For the systematic working of a mine it is most important that proper surveys of it be made. This is generally done by using an application of the compass, the miner's dial or a mining theodolite, the operation being MINES. termed dialling. It is done on a system of traversesurveying, the inclination and declination having also to be taken into account. After the ores have been brought to the surface they have generally to go through a series of operations termed dressing, the object of which is to get rid of the worthless portions and concentrate the richer. For this purpose the ore is usually subjected to a process of hand-picking or sorting, after which it may be broken up by a stonebreaker, and then crushed between a set of crusher-rolls, or pounded up fine by stamps. It may be then washed, for Fig. 5. Mueseler's Lamp, with gauze and glass cylinder. Fig. which there are a variety of machines, such as jigs, buddles, frames, besides numerous others. In some cases it may be necessary to calcine the ore, and after further pulverizing it to put it through such processes as tossing, packing, &c. There are besides, in the treatment of gold and silver ores, the various operations of amalgamation, which belong more properly to the subject of METALLURGY. These and a precise description of the dressing of ores cannot be entered upon here. Of late years the condition of the miners has been greatly improved by the introduction of the Metalliferous Mines Act (1872), and the Factory and Workshops Act, under which the dressing floors and surface operations come; but several anomalies still exist owing to the want of harmony of the two Acts. Thus although boys under fourteen cannot be employed on the floors they can work underground at twelve. The owner Mines belong to the tenant in fee-simple of the land, with the exception of gold and silver mines, which belong to the king by his prerogative; but by 1 Will. & Mary, c. 30, a mine of lead, copper, or tin is not to be considered a royal mine though silver be extracted from the ore. of land in fee-simple is the owner of everything which lies in a perpendicular direction under the surface to any depth. A tenant for life, unless his estate is without impeachment of waste, cannot dig earth, lime, clay, or stone, except for the repair of buildings or the manuring of the land. He cannot open a new mine, but he may work mines which are already open, and he may open new shafts for working veins of coal which have been already worked. A tenant in tail can cut down timber or open mines. The freehold of all copyhold lands is vested in the lord, and consequently the mines. In some cases a copyholder of inheritance has by the custom of the manor a right to the timber, and the lord has no right to dig mines, unless there be a custom which gives him the right. It is not 6. Dubruille's Lamp, with chimney. Fig. 7. Petroleum Lamp. uncommon for one person to be owner of the surface of the land and another of the mines beneath; and several persons may be owners of different kinds of mines lying above each other in the different strata. The formation of coal and its geological occurrence, together with an account of the coal-fields of Great Britain, have been treated of in the article COAL. Maps I., II., III., and IV. now given will show the distribution of coalbearing strata in England, and the geological structure in connection with each of the most important British coalfields. As regards the methods of working coal-mines there are many particulars in which they differ from those adopted in metalliferous mining; some of these may be briefly referred to here. The thickness of workable beds of coal generally varies from 3 or 4 to 8 or 9 feet; although sometimes, when several seams come together, they expand to 20 or 30 feet, of which we have an example in the "ten-yard coal" of Staffordshire. In every coal-field there are many seams at greater or less intervals, one below another, of which as many as three or four are frequently worked in the same mine. When the position of the beds of coal has been discovered, the first process is to sink a perpendicular shaft from the surface so as to intersect the various strata containing the coal, and of course as many of the beds of coal as are considered to be worth working. The upper portion, as far down as the solid rock, is either bricked or walled, and where the ground is weak this casing may be continued throughout. On reaching the coal, drifts are set off on each side, and the excavating of the coal is commenced. There are two modes of conducting the operations, namely, by what is called the "pillar and stall" and the "long-wall" methods. By the first of these, pillars of coal are left to support the superincumbent strata, so that roads may be carried into their faces. pillars are removed when there is no longer any necessity These for supporting the roof. By the second the whole of the coal is removed in one operation, and the roof alowed to subside and rest upon the debris of the seam. Roads are carried through the "gob." the roof being blasted down to afford sufficient height for the Leses to pass through. In either way roads laid with rails are carried into the coal faces, and upon these the tubs run in which the cus is conveyed to the shaft. Thus the operations continue, until the mine resembles a town of streets rectangularly arranged The water encountered in the above operations is drawn to the surface by a steam-engine erected at the top of the shaft, similar to those used in Cornish mines; but where there is little water it is so arranged as als, to raise the coal and rubbish, for which purpose either - corves" or baskets are commonly employed. In small coal-mines the ventilation is managed by separating a portion of the shaft from the larger part by an air-tight boarding, which is carried down to the bottom; but in large coal-mines another shaft is sunk at some distance from the first, and when the communication between them has been effected, the one is made downcast and the other upcast, the air being made to pass through the whole of the passages MINES. where similar operations will be commenced; small underground pits or staples" being sunk at intervals from the workings on the upper seam to those on the seam below, by which ventilation will be promoted. The mode in which the pitman proceeds in excavating the coal is by cutting a narrow fissure in the seam on each side of the bord with his pickaxe, and undermining the coal betweer (see fig. 8), and then cutting into and forcing down the isolated portion of coal; or, where the seam is thick, by detaching the great cubical mass thus prepared by blasting, two or three shots being sometimes simultaneously fired at the top of the seam. From 60 to 80 or ever 100 tons of coal may thus be brought down at once, when it is put into corves, drawn along a tram-road to the shaft, and thence raised by a steam-engine to the surface, where it is often passed over gratings or "screens" in order to separate the small pulverized coal from the larger masses. Of the various minerals for the extraction of which mines have been opened in Great Britain, it may be stated that gold has been worked in several places in Wales, both in placers or alluvial deposits and in veins. It has alw beer worked at Leadhills, Scotland, and at Croghan Kirshellagh, County Wicklow, Ireland. Although the depos.:s Fig. 8. While the workings on the first seam of oos are thus going on, the shaft may be sunk to a second or third seam. in some instances were rich they have seldom neered ex- worked for sulphur ore, but which also contained far bunches of copper. 7 mining is exclusively confined to the exarties of Cowall and Devon, where it occurs chiefly in a per grate or in the killas adjoining this rock. Operati s for its extraction have been carried on from remote antiquity, and it promises to continue for some time to come a source of revine to that district. The supplies of tin cre fr Queensiara, New South Wales, and the East Indian Islas 1.sve redneed the price to such an extent that may d Tes have had to be abandoned. Zinc is raised city as a seed day product from mines raising lead er copper cres. brae or sphide of zine being the chief source of t Aaroanese is now little worked in this ecuntry, theach formy raised in the Cornish district and in North Wa Autmony has beer worked in East Cornwall about Endlion, but the association of lead with it has proved detrimental te ts economic reduction. 7-ow has been raised in enormous quantities in the British Isles: the chief ores are these found in the coal measures associated with the seams of coal. Other important sources of supp's are the ores from the Lias and Oolites of Northamptonshire and other places. The hematite and chalybate depasts have provided rich ores and in tolerable abundant. In pattant deposits of these occur at Cleator Moor and at Ulverstone. Veins of hematite and chaly bite have been MINETTE. worked in Cornwall, but the supply of foreign ore has driven them out of the market. The iron ore measures in the tertiary basalts of Antrim at one time promised to prove an important source of supply, but of late years their production appears to have declined. It may be stated generally that, except in the case of the ecal and iron mining industries, mining in the British Isles Las declined enormously of late years. At present the tin mines of Cornwall and the lead mines scattered over the cantry, are almost the only metalliferous mines proving productive. The cause of this must be ascribed to the abundance of the supply of mineral from rich foreign deposits, which has so reduced the price of the metals that it is no longer profitable to extract and raise ores from the at depths to which our mines have been extended. MINETTE, in geology, is the name applied to a felsitic rock ecmposed of felspar and mica. The ground mass is sly microcrystalline, and in it are developed crystals magnesia, mica, and orthoclase, and plagioclase felspar; artz and hornblende sometimes occur. Mica diorite and a trop are names also applied to this rock. MINIÉ RIFLE, a species of military firearm (now superseded by later improvements), in which the ball, instead of being round, was conical, the base being concave, and the conical or pointed end being driven towards its object with much more force and velocity than the common ball. It received its name from Captain Minie. the inventor. In our contests with Russia and China it was found very effective. The Enfield Rifle was M.zis Rifle Ball. improvement on the Minié; and the Martini-Henry has rendered both the an Ild and the Minié obsolete. MIN IM, in music, a character or note formed of a d open head, and a stem descending on the left or g on the right *e first introduced, the minim was the shortest note in sc, as its name indicates. It is half as long in duraas the semibreve, and double as long as the crotchet. IL- minim measure of apothecaries is the sixtieth part a Sud drachm. 281 MIN IMS or MIN'IMI, a religious order which improved the Lumility of the Friars Minor (Franciscans) by callng them selves. Minimi, or the Least. They were instituted *x 1440 by St. Francis de Paul, and confirmed in 1473 by Sixtus IV., and by Julius II. in 1507. They had conterts in France and Spain. There were nunneries of the er, and one of these has given its name to the wellwn street in London called the Minories, where their twent formerly stood. Both friars and sisters went a-fect, and never put off their single coarse garment by Sht. MINING, MILITARY. See FORTIFICATION. MINISTERS OF STATE, the public functionaries wis conduct the business of the several departments of te. I use forming the executive government have been fay described under CABINET. The ambassadors and repuntatives of foreign states are also called ministers, and aded by diplomatic usage into three orders, the first gpapal legates and nuncios, and ambassadors Ly and extraordinary. [See AMBASSADOR.] The d class includes envoys, ministers plenipotentiary, and internuncios. The third class comprehends ministers det, ministers chargés-d'affaires, diplomatic consuls, and deputies or commissioners sent to international con[See CONSUL] A minister of the first class is d to both public and private audiences of the soveto whom he is accredited; a minister of the second MINNEAPOLIS. class to private audiences only. Those of the third class usually conduct their negotiations with the minister or secretary of state for foreign affairs. All representatives of foreign states are the natural protectors of the subjects of their own state in the country to which they are sent. MIN'IUM or RED OXIDE OF LEAD occurs associated with galena and other lead minerals, but not in sufficient quantity to be regarded as a source of lead. This mineral is found usually pulverulent. It is of a bright red colour, and is composed of the protoxide and binoxide of lead. Minium has the same composition as the red lead of commerce; and this article, which is used as a paint and in the manufacture of flint glass, is prepared artificially from pig-lead by heating it in a furnace till it becomes oxidized and converted into litharge. This substance is then placed on iron trays and heated in a current of air, which produces a higher state of oxidation, and red lead is formed. MINK is the name given to some small weasel-like carnivorous mammals belonging to the genus Putorius, and family MUSTELIDE, and forming the subgenus Lutreola. The mink approaches the marten more nearly than the weasel, in the form of its body, which is stout and from 15 to 18 inches long, not including the tail, which is about 8 inches in length and bushy. The toes are partially webbed, and the intervals between the large naked pads of the soles of the feet are not provided with hairs. Two species of mink are well known, so closely agreeing in size, form, colour, and habits, that but for their wide separation in distribution they would probably be regarded as one species. The European Mink (Putorius lutreola) is found chiefly in Russia, though formerly it extended into Germany. The colour varies from light yellowish-brown to dark brown, the tail being generally black; the edges of the upper lip are white. The under fur is soft and downy, with large coarse hairs intermingled. The fur is very valuable, and is often sold as sable. The American Mink (Putorius vison) is distinguished by its slightly larger size, more bushy tail, and dark upper lip. It is widely distributed throughout North America. The scent glands in this, as in the preceding species, are well developed; so that the mink yields only to the skunk in offensiveness. The fur is an important article of commerce, though less valuable than that of the European species. The mink is thoroughly amphibious in its habits, living near the banks of ponds and streams. It is an excellent swimmer and diver, and, like its congener the otter, runs well on land. It feeds on frogs, fishes, molluscs, crustaceans, small birds, and small mammals, such as rats, mice, and rabbits, and also makes extensive depredations on the poultry-yard. It makes its nest in burrows in the riverbanks and breeds in early spring, producing five or six young at a birth. Though exhibiting all the courage and ferocity of its allies, the mink, when taken young, is easily tamed, and is very generally kept by farmers in North America as a ratter, and also bred for the sake of its fur. MINNEAPOLIS, a city of the United States, in Minnesota, finely situated on the right bank of the Mississippi, at the falls of and opposite St. Anthony, which is incorporated with it. It is 8 miles west of St. Paul and 3 miles from the Minnehaha Falls. The headquarters of the flour manufacturing interests of the United States, and now a city of 100,000 inhabitants, it was, little more than thirty years ago, a mere hamlet, originating in a small grist mill for the convenience of a few soldiers. The first lumber mill was not built until 1848, and the village of St. Anthony Falls was surveyed in 1849. In 1854 there was built a flour mill, and the first suspension bridge was thrown across the Mississippi. Owing to the vast store of water power obtainable from the falls, the rapid progress of Minneapolis has every appearance of permanency and continuance. The |